Apparatus for applying adhesive to wax coated paper



H. E. HALLMAN APPARATUS FOR APPLYING ADHESIVE TO WAX COATED PAPER April15, 1941,

Filed Aug. 27, 1938 2 Sheets-Sheet 1 v m Wis INVENTOR'. Ilmafl ATTQRNEYSApril 15, 1941. AN 2,238,695

APPARATUS FOR APPLYING ADHESIVE TO WAX COATED EAPER Filed Aug. 27, 19382 Sheets-Sheet 2 INVENTOR. J'C'aro/a j-("a ll man 7&2 ATTORNEYS 7Patented Apr. 15, 1941 APPARATUS FOR APPLYING ADHESIVE TO J WAX COATEDPAPER Harold E. Hallman, Catonsville, Md.

Application August 27, 1038, Serial No. 227,115

8 Claims.

My invention relates to a novel apparatus for applying glue to a bagbottom and more specifically my invention relates to an apparatus forreceiving and heating glue containing a volatile solvent and applyingsaid glue containing said volatile solvent to a wax coated paper.

In the prior art there has been much difiiculty in sealing wax coatedpaper inasmuch as the ordinary glue applied thereto fails to secure areal grip upon the wax coated paper inasmuch as the wax is resistant topenetration. It has been suggested that glue containing a solvent beemployed so that the solvent contained therein 1 could strike throughthe wax to allow the glue be heated to obtain the proper action.However,

if the glue and solvent mix be heated in the glue pot, the solvent whichis customarily volatile is driven off and its action lost.

My apparatus is eiIective when an adhesive mix comprising glue andvolatile solvent is employed and also when an adhesive mix comprisingglue or adhesive without volatile solvent is employed. The advantages ofnot heating for an extended period are applicable even when no volatilesolvent is used.

Accordingly, I have devised a novel apparatus by means of which the glueand solvent mixture can be applied in a hot state without the loss ofthe important volatile solvent so that the optimum action of the glue isobtained. My apparatus further provides for the economical andaccurately predetermined delivery of proper amounts of glue and solventmixture to the wax paper.

My apparatus comprises a drum which revolves in a glue pot whichcontains the glue and volatile solvent mix which shall be termedadhesive mix hereinafter. The adhesivermix is carried up on therevolving drum and a doctor roll gauges the amount of adhesive mix thatis carried by the roll. Placed adjacent to the adhesive roll and adaptedto contact it after the adhesive mix has been engaged by the doctor rollis another I roll carrying a segment which segment contacts the drum andreceives an application of the adhesive mix. Positioned adjacent to thisroll one or more paste bars on the applicator roll.

' The applicator roll revolves in timed relation with carrying thesegment and adapted to cooperate therewith is a further roll having acutout section which carries a paste bar adjacent to which is a heatingelement.

The roll carrying the segment and the roll carrying the paste bar aretimed to cooperate so that the segment on the first roll contacts thebag sections passing beneath the roll so that the applicator rollapplies a line of adhesive mix to the bag section whereupon the end ofthe bag section is turned up upon the adhesive line to form the bagbottom.

An added advantage of my apparatus lies in the fact that the heatedpaste bars act not only to heat the volatile solvent and adhesive mixbut also at the same time that the paste bars apply the heated adhesivemix to the wax coated paper, the heating action of the heated paste baron the wax coating of the paper tends to melt the wax coating to allowthe penetration of the adhesive mix through the fibres of the paperbeneath the wax coating. Thus I obtain a dual beneficial action by theuse of the heated paste bars, said heated paste bars, as stated, actingboth to heat the adhesive mix which is applied to the wax coated paperand also acting to heat the wax coating to cause the same desirably tomelt to allow the penetration of the adhesive through tothe paper.

In addition to applying transverse stripes of paste to form the bagbottom, I provide an apparatus comprising a heated disc which appliespaste longitudinally along the paper to provide the longitudinal bodyseam of the bag to be formed. By employing a heated disc for applyingthe adhesive and volatile solvent mix, I again obtain manifoldadvantages. First, the heated disc heats the volatile solvent andadhesive mixture so that it is applied hot to the wax coated paper andsecondly, the heated disc acts to heat the wax coating of the papercausing it to melt to allow the penetration of the applied adhesive andsolvent.

I further propose employing wax coated paper having a thicker inside waxcoating and a thinner outside wax coating. That is, the wax coat-.

ing on the interior of the bag is thicker than that on the exterior ofthe bag. This is an advantage in the final product since it is desirablethat the contents of the bag, which may be greasy, be prevented fromstriking through to the fibres of the paper and impairing the paper. Thewax coating on the outside of a the bag, though thinner than the inside,wax coating, is sufficiently thick to perform its function of renderingthe bag'substantially moisture proof. By employing the respectivelythicker and thinner coatings of wax, I also provide for more efficientlyjoining the wax coated paper in the formation of the bottom of the bagand also in the longitudinal formation of the body seam. Thus, by meansof my particular apparatus set forth, I take care to apply the adhesivemix by means of a heated member as for example a paste bar or heateddisc respectively with re-. spect to the bottom of the bag and body seamof the bag so that the heated member applies the adhesive to that sideof the wax coated paper having the thicker wax coating. Thus, when thestrike through the thinner wax coating to the paper to secure a perfectjoint. The coordination of the use of a relatively thicker coating ofwax on one side of the paper and a relatively thinner coating on theother, and the application of the heated adhesive mix to the thickercoating by means of a heated applicator member makes possible theformation of a strong and secure joint wherein the adhesive has struckthrough the wax coatings to the fibres of the paper.

Accordingly, it is an object of my invention to provide a novelapparatus for applying a heated mix of glue and solvent to paper.

It is a further object of my invention to provide a novel apparatus thatpicks up a glue and volatile solvent mix in an unheated state andapplies it to wax coated paper in a hot state without loss of volatilesolvent.

It is still a further object of my invention to provide-a novelapparatus comprising a roll positioned to revolve in a bath of adhesivemix, a doctor for the roll, a roll carrying a segment adapted to pick upthe adhesive mix on the segment, an applicator roll carrying segments:with adjacent heater means, the applicator segments being supplied withadhesive mix by the segments of the adjacent roll, the applicatorsegments being adapted to heat the adhesive mix and apply it to the vwaxpaper.

Other objects of my invention will become apparent from the descriptionwhich follows taken in connection with the drawings in which,

Figure 1 is a perspective of the apparatus of my invention.

Figure 2 is a. perspective of a bag showing the position of the appliedglue and solvent mix.

Figure 3 is a perspective of a heated disc means for applying the glueand solvent mix to form the longitudinal seam.

More specifically, in Figure 1 is a glue pot l which contains anadhesive mix 2 comprising glue and a volatile solvent such as alcohol,ether, acetone, or similar low boiling point volatile solvent. Immersedin the adhesive mix and adapted to rotate therein is a glue pot roll 3which retates on the shaft 4 in the direction indicated by the arrow.Positioned adjacent to the glue pot roll 3 is a doctor roll 6 whichrotates on a shaft 1 and may be adjustably positioned with respect tothe glue pot roll 3 so as to measure I the amount of adhesive mixcarried up upon the roll 3. Positioned adjacent the glue pot roll 3 is afurther segment roll 9 rotating on a shaft l and carrying a pastesegment II. The paste segment I I is adapted to contact the glue potroll '3 and pick the adhesive mix therefrom. The

paste segment II is adapted to contact the paste bars l2 and I3 andtransmit the paste thereto. The paste bars l2 and I3 are set in anapplicator roll l5 and are heated by the adjacently mounted stripheaters l6 and H. The strip heaters l6 and Il are heated by means of theelectrical coils l8 and I9 which are supplied through the conduits and2|. A conventional commutator and brush arrangement secured on the endof the shaft 23 supplies the electricity to effect the heating of thestrip heaters l6 and IT. The paste bars l2 and I3, as exemplified by theposition of paste bar I3, applies the adhesive mix to the proper portionof the bag which travels on the belt 3|, which belt 3| moves about thedrum 32. The paste bars apply the adhesive mix in the form of a pasteline 34 on the bag 30. The overlap of the longitudinal seam is indicatedat 35; the serrated edges 36 and 31 are formed by'the cutting mechanismthat severs the tube of wax coated paper into proper lengths. Althoughit forms no part of the present invention, it is to be noted that thebag bottom is formed by folding over the end 36 on the glue line 34.

In Figure 3 I show means for applying the heated adhesive and solvent,to the edge ofwax coated paper to form a longitudinal seam. In the pot40 is the adhesive and volatile solvent mix 4|. A disc revolves in theadhesive and volatile solvent mix and carries the mix up upon itsperiphery. The disc 42 is heated by a cartridge heater 43 which receivesa source of current through the wires 44. The revolving heated disc 42applies a line of adhesive 46 to the wax coated paper 41 which movesabout the roll 48. As the wax coated paper 41 travels after being givena layer of adhesive and solvent 46, it is folded over a conventionalformer (not shown) to form the tubular section 49 with the seam 50.

Preferably the wax coating on that side of the paper where the adhesivemix is applied is thicker than the wax coating on the opposite side ofthe paper. Thus, the heated adhesive is applied by the heated disc tothe thicker wax coating and strikes through such thicker coating to thefibres of the paper. Shortly after that portion of the wax coated paperwith the heated adhesive applied thereto is foldedover on the matchingfold to form the longitudinal seam. Preferably the external coating ofthe paper is thinner and thus the heated adhesive strikes through thisthinner coating to secure itself to the fibres of the paper,

whereby a strong seam in which the adhesive is secured to the paperitself on both sides is obtained.

The operation of my apparatus is as follows:

A suitable adhesive mix comprising glue or paste in combination with avolatile solvent as has been described above is mixed thoroughly andplaced in the pot I. This adhesive mix is of such a nature that I havefound it extremely effective when applied hot to the wax coated paper.It is best in the heated state because/the adhesive mix acts to dissolvethe wax coating of the paper both by reason of its heating andv alsobecause of the solvent action of the contained solvent. Dissolving thewax, it strikes /through to the paper beneath the wax and thus secures astrong grip to effect a good bottom seal. out this striking throughaction, the glue would have an imperfect bond to the wax.

However, the adhesive mix cannot be heated in the not since it wouldmerely tend to thicken the glue driving off the volatile solvent, andfor this reason it is best heated at that point when Withit is about tobe applied to the wax coated paper. Accordingly, the adhesive mixcomprising glue and solvent in the pot is simultaneously mixed and,

carried up on the roll 3. The doctor roll 6 by proper adjustment of itsdistance from the glue roll 3 determines the thickness of the layer ofadhesive mix carried by the roll 3. Thus after the adhesive mix haspassed the doctor roll 6 it is at a predetermined level on the glueroll. The glue on the roll 3 is picked up by the segment ll mounted onthe roll 9, and because of the timed relation of the roll 9 and IS, thesegment roll 9 applies the adhesive mix to the paste bar l2; thenapplying a fresh portion of the adhesive mix to,

the paste bar l3, The paste bars l2 and I3 are maintained'in a heatedstate by means of the adjacently mounted strip heaters l6 and I1.

, The adhesive mix is on the paste bar sufllciently long to be heatedwithout being heated so that any quantity of the volatile solvent islost by evaporation. The paste bars are timed with the movement of thebag segments 30 which move along the'belt 3| so that the paste barapplies paste on to the bag segments on the predetermined paste line 34,whereupon the hot adhesive mix acts to melt the wax and with the aid ofthe volatile solvent strikes through to the fibers of the paper, so thatwhen the end of the paper segment is folded over a good bond is secured.

Various modifications of this process and apparatus are within the scopeof my invention. The applicator roll may have one or more paste bars andthe segment roll may have as many segments as is feasible, dependingupon the size of the roll and its correlated speed with the applicatorroll.

Although I have shown this particular device as particularly applicablefor layinga transverse glue line, it may be employed to apply glue inany desired form.

Attention is directed to the fact that in the apparatus described in thepresent invention, the heating ,means is in a protected position in therecessed or guarded portion of the drum l5. Thus during the rotation ofthe drum, the strip heater I6 is substantially protected from thechilling effect of air currents because of its particular position asshown. Inasmuch as it is desired to maintain the paste .bar at arelatively high temperature and to maintain this high temperatureuniform, the protected position of the strip heater is important.

If in the formation of bag bottoms as shown in Figures 1 and 2 of mydrawings a wax coated paper is employed in which the inside coating isthicker than the outer coating and it is desired to obtain the superiorbond described hereinbefore, then I may apply the line of hot adhesive34 to the bottom flap 36, whereby the heated adhesive is thus applied'tothe thicker inner coating of the wax paper by the heated paste bar andis then folded over, whereupon the outer thinner wax coating of thepaper is melted and the adhesive strikes through the outer thinnercoating to effect a bond between the paper of both com-- ponents of thefold. Although in Figures 1 and 2 I have shown the adhesive mix beingapplied to the outer coating, I may, if I employ the thicker innercoating and thinner outer coating described hereinbefore, apply theheated adhesive to the innercoating of the flap 36 instead of to the.outer coating as shown in Figures 1 and 2.

Although I specifically refer throughout this specification to waxcoated paper I include within the scope of my invention paper or anyother sheet material as for example, non-fibrous Cellophane, as thepaper material and any heat sensitive material which has characteristicscorresponding to wax as the coating material. Thus I have set forth waxand paper by way of example only and I intend that this should beunderstood to mean materials that have equivalent functions in this art.The appended claims should be read in that light.

I claim:

1. An apparatus for applying a mix comprising a volatile solvent and anadhesive to coated paper which comprises a tank adapted to contain a mixof volatile solvent and an adhesive, means for withdrawing the mix fromthe tank, a paste bar, means for heating the paste bar, means forapplying said mix to said paste bar.

2. An apparatus for applying a mix comprising a volatile solvent and anadhesive to coated paper which comprises a tank adapted to contain a mixof volatile solvent and an adhesive, a roll positioned to be partiallysubmerged in the mix of volatile solventand adhesive and to carry up theadhesive mix on its surface, a paste bar, a travelling segment adaptedto contact said first mentioned roll and carry the adhesive therefrom toa paste bar, and means for heating said paste bar.

3. An apparatus for applying a mix comprising a volatile solvent and anadhesive to coated paper which comprises a tank adapted to contain a mixof volatile solvent and an adhesive, a roll positioned to be partiallysubmerged in the mix of volatile solvent and adhesive and to carry upthe adhesive mix on its surface, a doctor adjacent said roll, atravelling segment positioned on a secured roll adapted to contact saidfirst mentioned roll and carry the adhesive therefrom, a paste bartravelling in such a path as to periodically contact said travellingsegment, said paste bar being rotated about a given point and means forheating said paste bar.

4. An apparatus for applying a mix comprising a volatile solvent and anadhesive to coated paper which comprises a tank adapted to contain a mixof volatile solvent and an adhesive, a roll positioned to be partiallysubmerged in the mix of volatile solvent and adhesive and to carry upthe adhesive mix on its surface, a doctor roll spaced from but adjacentto said roll, a travelling segment positioned on a secured roll, saidtravelling segment moving so as to contact said first rolland secure themix of volatile solvent and adhesive therefrom, a paste bar travellingin such a path as to periodically contact said travelling segment, saidpaste bar being rotated about a given point and heating means mountedadjacent to said paste bar.

5. An apparatus for applying a mix comprising a volatile solvent and anadhesive to coated paper which comprises a tank adapted to contain a mixof volatile solvent and an adhesive, a roll positioned to be partiallysubmerged in the mix of volatile solvent and adhesive and carry up theadhesive mix on its surface, a doctor roll spaced from but adjacent tosaid roll, a travelling segment positioned on a secured roll, saidtravelling segment moving so as to contact said first roll and securethe mix of volatile solvent and adhesive therefrom, paste barstravelling in such a path as to periodically contact said travellingsegment, said paste bars being rotated about a given point and means forheating said paste bars.

6. An apparatus for applying a mix comprising a volatile solvent and anadhesive to coated paper which comprises a tank adapted to contain a mixof volatile solvent and an adhesive, 2. roll positioned to be partiallysubmerged in "the mix of volatile solvent and adhesive and carryyp theadhesive mix on its surface, a doctor roll spaced from but adjacent tosaid roll, a travelling segment positioned on a secured roll, saidtravelling segment moving so as to contact said first roll and securethe mix of volatile solvent and adhesive therefrom, paste barstravelling in such a path as to periodically contact said travellingsegment, said paste bars being rotated about a given point, stripheaters mounted adjacent to said paste bars.

'7. An apparatus for applying a mix comprising a volatile solvent and anadhesive to coated paper which comprises a tank adapted to contain a mixof volatile solvent and an adhesive, a roll positioned to be partiallysubmerged in the mix of volatile solvent and adhesive and carry up theadhesive mix on its surface, a doctor adjacent said roll, a travellingsegment adapted to contact said first mentioned roll and carry theadhesive therefrom, a drum having a cutaway sector, a paste bar securedwithin the cutaway sector of said drum, means for heating said paste barpositioned within said sector.

8. An apparatus for applying a mix comprising a volatile solvent and anadhesive to coated paper which comprises, a drum having a cutawaysector, a paste bar secured within the cutaway sector of said drum,means for heating said paste bar positioned within said sector.

HAROLD E. HALLMAN.

